To establish, implement and maintain the Repository Data Center for the joint AIDS contracts effort between the Intramural Research Program (OSD/IRP) and the Microbiology and Infectious Disease Program (MIDP). This effort is a study of the epidemiology, pathogenesis, natural history, susceptibility, and causative agents of Acquired Immune Deficiency Syndrome (AIDS). The data base will contain information on approximately two million medical specimens from six contractors. Specimens from selected patients will be sent to qualified investigators for special testing and biological research. The data on these removals from the repository, on the tests and research to be performed, and the results also will be entered and maintained in the database. To coordinate and evaluate flow cytometry studies of patient PBL by the AIDS contractors.